Multilayer paper hose



v June 3, 1969 H. BECK 3,447,573

MULTILAYER PAPER HOSE Filed March 29, 1966 Sheet of 2 lnveglon:

' BY Q- June 3, 1969 H. BECK 3,447,573

MULTILAYER PAPER HOSE Filed March 29, 1966 Sheet 2 5r 2 Fig.3

lnv ntor: H e

ilNZ IC-K United States Patent US. Cl. 138122 5 Claims ABSTRACT OF THE DISCLOSURE There is disclosed a multilayer paper hose in which a wire coil is encompassed by several overlapping layers of a lengthwise corrugated spirally wound web of stretchable paper. The pitch of the wire and the web are substantially the same and the turns of the coil engage the valleys of the corrugations on the inside of the paper layers whereby the web from which the layers are wound is such that it extends across several turns of the coil. The overlapping margins of the paper web are bonded to each other and a string spirally encompasses the outside of the paper layers and engages the valleys of the corrugations on the outside of the paper layers.

The present invention relates to a multilayer paper hose.

There are known paper hoses formed of a spirally wound paper web the longitudinal margins of which overlap each other and are bonded together. As hoses of this kind do not include a re-enforcing helical wire or strip they permit only a comparatively large bending radius. Any attempt to apply a fairly sharp bend to the hose tends to cause a collapse or break-in of the hose or at least a substantial reduction of the inner diameter of the hose. Such limited bending capability is not appreciably improved by the accordion-like folds on the inside and the outside of the hose since the pitch of the folds is inherently too small to effect an appreciable increase of the permissible bending radius by opening and closing, respectively, of the folds. For the same reason, it is also not practical to compress the hose lengthwise or to twist the hose to a useful extent. Hoses of the kind above referred to also have very little radial strength. Attempts have been made to improve the radial strength by inserting aluminum or plastic strips between the paper layers of the hose. While such inserts slightly improve the radial strength of the hose, they further reduce the bending capability and the flexibility of the hose which are stated before, is rather limited even without such inserts.

There are further known multilayer hoses including a re-enforcing helical wire or strip. Hoses of this kind are made of an elastomer such as polyvinylchloride. The hoses are formed by spirally winding a strip of the hose material about a helical wire so that the windings overlap each other. The overlapping margins of the strips are then suitably bonded together for instance by heat sealing or gluing. Hoses of this kind can be axially compressed but will immediately re-expand to substantially the initial length due to the inherent flexibility of the hose material.

It is an object of the invention to provide a novel and improved multilayer paper hose which permits a smaller bending radius than was heretofore obtainable for a hose of a given diameter and the configuration of which, including the inner diameter of the hose, can be permanently altered within certain limits by axially compressing of stretching the hose.

It is also an object of the invention to provide a novel and improved multilayer paper hose which due to its flexibility and capability of changing its configuration, can be force fitted upon a socket or nipple and will remain Patented June 3, 1969 securely attached without further fastening means such as a hose clamp.

A further object of the invention is to provide a novel and improved multilayer accordion type paper hose which is internally re-enforced by a spiral coil wound of stiff wire and externally by a soft string wound about the hose, preferably under tension and glued to the hose wall, both the wire and the string being placed in the valleys of the accordion folds.

Still another object of the invention is to provide a novel and improved multilayer paper hose the inner wall of which is comparatively smooth thereby increasing the fields of use for which the hose is suitable. 7

Other and further objects, features and advantages will be pointed out hereinafter and set forth in the appended claims constituting part of the application.

In the accompanying drawing a preferred embodiment of the invention is shown by way of illustration and not by way of limitation.

In the drawing:

FIG. 1 is a diagrammatic view of a device for forming a multilayer paper hose according to the invention.

FIG. 2 is a fragmentary section of the wall of a hose according to the invention.

FIG. 3 is a diagrammatic view of a bent section of a hose according to the invention, and

FIG. 4 is a fragmentary view of a hose wall portion a part of which is compressed.

Referring now to the figures in greater detail, the hose making device as exemplified in FIG. 1 comprises a mandrel 3 coacting with a profiled feed roller 2 and a profiled counter roller 4. The two rollers are staggered in reference to each other.

A re-enforcing helical coil made for instance of galvanized or tinned steel or other stiff wire 5 is formed on mandrel 3 by guiding it upon the mandrel by means of a feed roller 7 and bending it by a bending device 6 so that the wire has a predetermined and constant pitch and a substantially uniform diameter. Bending devices suitable for the purpose are known in the art and described for instance in the assignees prior patent 3,089,- 535. Roller 7 is so set in reference to mandrel 3 that the wire is bent tighter than would be required for the intended final diameter of the re-enforced coil. This has the advantage that the final diameter of the coil after expansion of the same due to the inherent flexibility of the wire can be readily adapted to the diameter of the finished hose.

A web 1 made of a stretchable paper preferably crepe paper is wound under tension about the wire coil on mandrel 3. The width of the web is such that it covers several turns of the re-enforcing coil such as four turns. The number of coil turns covered by the paper web determines the number of layers which the finished hose will have. As is well known, the overlaps formed by the paper can be calculated from the number of grooves in the roller 2, four grooves being shown. The equation governing such calculation is:

Number of grooves in the roller minus one=number of layers or overlaps of the web As is evident, in the first groove of roller 2 the paper is fed in. In the second groove the wire is already covered with paper. In the third groove the first overlap with the paper layer underneath is formed and in the fourth groove the second overlap is formed so that three superimposed layers of papers are formed as is shown in FIG. 2 by layers la, 1b and 1c. As is evident corrugations are formed in the paper layers by the action of the coil turns and the profiled rollers.

Roller 4 also has four grooves and all the grooves in rollers 2 and 4 have the same depth and width. However, the grooves in the rollers may also be different from each other. As is apparent, the first groove of roller 4 receives the wire only. Hence, the depth of the groove need only to match the diameter of the wire. The second groove must receive the wire and one layer of paper, the third groove the wire and two layers of paper and the fourth groove the wire and three layers of paper. In other words, the depths of the grooves in roller 4 must either increase from groove to groove in the winding direction, or as shown, all grooves must be so dimensioned that they are capable of receiving the wire and three layers of paper if it is desired to make all grooves alike.

The overlapping rims of web 1 are suitably bonded to each other so that a closed hose wall is formed. Devices suitable for applying an adhesive are well known in the'art and do not constitute part of the invention. The adhesive may be applied by an applicator to web 1 on the side thereof which faces mandrel 3. The paper layers formed as hereinbefore described are pressed together by the action of rollers 2 and 4 so that the adhesive material will strongly join the layers, As a result, the several layers forming the hose are now no longer capable of being displaced in reference to each other.

A soft thread or string 8 such as a string made of suitable fibrous material is fed from the same direction as web 1. After several superimposed paper layers are formed, the string is placed in the valleys of the corrugations formed in the hose. The string will remain suitable and conventional guiding means (not shown).

Feeding of the string is preferably effected under tension thereby exerting a radial pressure upon paper layers 1a, 1b and 1c. A corresponding counter pressure is produced by the turns of the re-enforcing coil on the mandrel. Due to the radial pressure exerted by string 8, the friction between hose layers 1a, 1b and 1c is increased thereby strengthening the capability of the hose to absorb the lateral stresses which occur in the hose due to adhesion of the layers when the hose is bent.

The multilayer paper hose according to the invention, has several marked advantages. Due to the comparatively high pitch of the re-enforcing coil formed by wire 5 and of web 1, a rather narrow bending radius can be applied to the hose as is evident from FIG. 3. This figure shows how the valleys 9 of the corrugations formed I in the hose move inwardly in an accordion fashion as it is indicated at 10 in FIG. 3. In other words, the wider the valleys 9 are, or in other words, the higher the pitch is, the larger become the folds 10 in the compression zone of the hose. Moreover, the sum total of the width of the involved folds 9 is a measure for the potential bending radius. Accordingly, the bending radius is, in practice, limited only by the bending position in which the side walls of the hose defining the valleys 9 abut each other when the folds 10 are formed.

Due to the possibility of closing the valleys 9 or in other words, of opening the folds 10, the hose can also be axially pushed together to a substantial extent. Since the paper material used for forming the hose is not elastic, the folds remain substantially constant in shape. Accordingly, the inner diameter of the hose can be permanently changed within the range of several millimeters depending upon to what the extent the hose is or can be compressed in axial direction. This is, in practice, very advantageous since a hose with respect to its inner diameter is bound to have a comparatively wide range of tolerances and the tolerances with respect to the outer diameter of a socket or nipple upon which the hose has to be fitted are also generally rather wide in practice. As is now evident, the inner diameter of a hose according to the invention can be adapted, by stretching or compressing the hose, within certain limits to the outer diameter of the socket or nipple to be used. Furthermore, the folds 10 which are formed when the hose is compressed (see FIG. 4) exert a radial pressure upon the socket or nipple. The friction thus obtained is in many instances suflicient to secure the hose so that additional fastening means such as hose clamps are not necessary.

The hose according to the invention, also permits a limited axial torsion.

A hose according to the invention, has the further advantage that the inner wall thereof is comparatively smooth. As is clearly shown in FIG. 2, the wire turns fill substantially the inner valleys of the corrugations and the web portions between adjacent turns are somewhat flattened so that the interior of the hose has substantially the same diameter along its entire length. In this connection, it should be pointed out that the fold formations as shown in FIG. 4 are exaggerated. In actual practice, the folds are considerably shallower. Due to the stiffness of the several layers of the web 1 which form the hose, the same is initially comparatively rigid. When now the hose is initially bent, permanent folds 10 are formed at the pressure side of the bent hose portion (see FIG. 3). When now the hose is bent in the opposite direction, the folds 10 previously formed are reopened. As a result, the hose remains substantially smooth for its entire length except at the pressure side of the hose portion at which the bending is effected. This feature of the hose is of particular importance when the hose is used for a purpose requiring substantial flexibility when the hose is installed but retention of the hose shape when the installation is completed. Such requirements are present, for instance, when the hose is used as a heater hose or as a ventilator hose in an automobile.

In the event it is desired that the hose is highly flexible, such high flexibility can be readily obtained by axially compressing the hose so that the inner folds 10 are formed which are shown in FIG. 4. The size of such folds is an indication of the flexibility of the hose.

When a hose is formed of an elastic hose material as has been described before in connection with conventional hoses made of a material such as polyvinylchloride, the compression and pull forces are absorbed by the hose material itself. With a hose according to the invention, in which the flexibility is primarily obtained by the formation of folds 10, such folds will open and close before the hose material itself is subjected to pull or pressure.

Another advantage of the hose according to the invention is that smaller forces are required for the opening and closing of the folds than are required when the hose material itself is subjected to stretch or compression forces.

While the invention has been described in detail with respect to a certain now preferred example and embodiment of the invention, it will be understood by those skilled in the art, after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended, therefore, to cover all such changes and modifications in the appended claims.

What is claimed is:

1. A multilayer paper hose comprising in combination:

a re-enforcing wire coil of uniform diameter;

at least two overlapping layers of a web of stretchable paper spirally wound about the turns of said coil, said web being lengthwise corrugated and adjacent turns thereof being separated by a flattened web portion, the pitch of the coil turns and of the web being substantially the same, the turns of the coil engaging the valleys of the web corrugations in the web on the outside of said paper layers there-' by preventing outward bulging of the hose due to internal pressure.

2. A multilayer paper hose comprising a re-enforcing wire coil of uniform diameter, at least two overlapping layers of a lengthwise corrugated spirally wound web of stretchable paper encompassing said coil turns, the pitch of the wire turns and the web being substantially the same, the turns of said coil engaging the valleys of the web corrugations on the inside of said hose and the width of said web extending across more than one turn of said coils, the wire turns in conjunction with the web portions extending between adjacent turns forming a continuous inner hose wall of substantially uniform diam eter, the overlapping margins of said web layers being bonded to each other, and a string spirally encompassing the outside of said paper layers and engaging the valleys of the corrugations in' the web on the outside of said paper layers thereby preventing outward bulging of the hose due to internal pressure.

3. A multilayer paper hose according to claim 2, wherein said web is a crepe paper web.

4. A multilayer paper hose according to claim 2, wherein said string is a soft fibrous string adhered to the outside of said paper layers.

5. A multilayer paper hose according to claim 2, wherein said string is under tension.

References Cited UNITED STATES PATENTS 1,388,467 8/1921 Keller 138122 2,181,084 11/1939 Aken -7 174-108 2,365,286 12/1944 Moseley et al. 138l31 XR 2,550,099 4/1951 Vance 138l22 2,597,806 5/1951 Martin 138122 LAVERNE D. GEIGER, Primary Examiner.

H. K. A-RTIS, Assistant Examiner.

US. Cl. X.R. 138144 

